EFFECT OF ACIDIFICATION ON STARTER PIG PERFORMANCE AND NUTRIENT DIGESTIBILITY T. L. Weeden, J. L. Nelssen, J. A. Hansen, and K. L. Richardson
Summary One hundred ninety-six pigs (21 d of age and 12.3 lb initial wt) were used to evaluate 1 the effect of adding an organic acid blend (OAB) to starter diets on growth performance and nutrient digestibility. The four dietary treatments consisted of a control diet and the OAB replacing corn at 3, 4.5, and 6 lb/ton in both phases 1 and 2. In phase 1 (0 to 14 d) diets, contained 20% dried skim milk, 20% dried whey, and 5% soybean oil. Phase 2 diets (15 to 35 d) contained 10% dried whey and 5% soybean oil. There was no response in ADG, FI, or F/G to the addition of OAB to starter diets in either phase 1 or phase 2. Fecal samples were collected on d 12 (phase 1) of the experiment via rectal massage, and apparent digestibility of nitrogen and dry matter were calculated using chromic oxide (.25%) as an indigestible marker. Nitrogen and dry matter digestibility decreased linearly with increasing levels of OAB. This trial demonstrates that addition of OAB has no effect on performance when pigs consumed high milk-product diets. (Key Words: Starter, Performance, Digestion, Acid.) Introduction The early-weaned pig has an immature digestive system and is somewhat limited in digestive capability; therefore, lowering the pH of the diet by feeding combinations of organic acids may improve digestibility and growth performance of early weaned pigs. Previous research has concentrated on addition of fumaric, hydrochloric, citric, or phosphoric acids to simple corn-soybean meal diets at levels of 1 to 4%, resulting in 5 to 10% improvements in feed efficiency only in the first 2 wk postweaning. The objective of this experiment was to determine the effect on pig performance and nutrient digestibility from addition of lower inclusion rates of an organic acid blend (OAB) to high nutrient density starter diets during phase 1 (0 to 14 d) and more simple diets during phase 2 (15 to 35 d). Procedures A 5-wk growth trial was conducted to evaluate the effects of various levels of OAB on pig performance and apparent nutrient digestibilities. Dietary treatments included OAB levels of .150, .225, and .300% of the diet. These levels were attained by replacing corn from the control diet with 3, 4.5, or 6 lb/ton of OAB, respectively. One hundred ninety-six 1
The authors express appreciation to SmithKline Animal Health Products, which donated the ® Stacidem for testing. 62
crossbred pigs weaned at 21 ± 2 d, with an average weight of 12.3 lb were utilized. Pigs were housed in an environmentally controlled nursery with feed and water supplied ad libitum throughout the experiment. Pigs were allotted by litter and sex within weight blocks to the four dietary treatments. There were seven replications per treatment with seven pigs per pen. Feed intakes per pen and individual pig weights were recorded weekly. On d 12 postweaning (phase 1) fecal samples were collected via rectal massage and frozen for later analysis. Apparent digestibilities of dry matter and nitrogen were calculated using chromic oxide (.25%) as an indigestible marker. Compositions of the control diets are shown in Table 1. A pelleted diet containing 40% milk products and 5% soybean oil was fed during phase 1 (0 - 14 d) containing 1.45% lysine, .90% Ca, and .80% P. In phase 2 (15 to 35 d), pigs were fed a meal diet containing 10% dried whey, 5% fish meal, and 5% soybean oil and formulated to contain 1.25% lysine, .90% Ca and .80% I? Results and Discussion The effect of OAB on growth performance is shown in Table 2. Pigs fed the OAB diets showed no improvement over the control diet for ADG, FI, or F/G in phase 1, phase 2, or the cumulative 5-wk experiment. In phase 1, a linear (P
